crypto config: update man pages and examples

Signed-off-by: Fabio M. Di Nitto <fdinitto@redhat.com>
Reviewed-by: Jan Friesse <jfriesse@redhat.com>

conf/corosync.conf.example

@@ -5,6 +5,7 @@ totem {
 	# crypto_cipher and crypto_hash: Used for mutual node authentication.
 	# If you choose to enable this, then do remember to create a shared
 	# secret with "corosync-keygen".
+	# enabling crypto_cipher, requires also enabling of crypto_hash.
 	crypto_cipher: none
 	crypto_hash: none
 

conf/corosync.xml.example

@@ -13,6 +13,7 @@
 	Used for mutual node authentication. If you choose to
 	enable this, then do remember to create a shared
 	secret with "corosync-keygen".
+	enabling crypto_cipher, requires also enabling of crypto_hash.
 -->
 <totem version="2" crypto_cipher="none" crypto_hash="none">
     <!--

man/corosync.conf.5

@@ -177,6 +177,7 @@ The default is sha1.
 crypto_cipher
 This specifies which cipher should be used to encrypt all messages.
 Valid values are none (no encryption), aes256, aes192, aes128 and 3des.
+Enabling crypto_cipher, requires also enabling of crypto_hash.
 
 The default is aes256.